Riva valvespring swap - help??

Trying to do the valvespring swap ... I pressurize the cylinder to about 80 psi, I can hear and feel some air leaking out of the exhaust manifold bell (J pipe is off). Then when I start to crank down the Riva tool, as soon as I crank down the spring, I get air rushing out the exhaust (or intake depending on which valve I try), and the valve does not seem to stay up, it just continues to drop as I compress the spring. ??? Am I doing something wrong?? Are all my valves shot at 150 hrs? As soon as I compress the spring, all the air pressure in the cylinder does not seem to hold the valve up, it seems to push past the valve, not keeping the valve up. Help?? Is possibly the air pressure too high, or??

Vern you will have some loss of pressure. I kept the air compressor at 120 p.s.i. and when it dropped bellow it. It would turn on automatically. IT NEEDS to or ....

Also Jerry has you covered. All that is happening is your retainer is in its seat real good and a little tap with the socket will free it and you will be ok.
Also for safty and piece of mind. Put some rags in areas so as to catch any retainers you may drop. People have done it and I did too, but I had rags to catch them.
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